Question: Umaima is 5 times as old as Jessica and is also 16 years older than Jessica. How old is Umaima?
Solution: We can use the given information to write down two equations that describe the ages of Umaima and Jessica. Let Umaima's current age be $u$ and Jessica's current age be $j$ $u = 5j$ $u = j + 16$ Now we have two independent equations, and we can solve for our two unknowns. One way to solve for $u$ is to solve the second equation for $j$ and substitute that value into the first equation. Solving our second equation for $j$ , we get: $j = u - 16$ . Substituting this into our first equation, we get the equation: $u = 5$ $(u - 16)$ which combines the information about $u$ from both of our original equations. Simplifying the right side of this equation, we get: $u = 5u - 80$ Solving for $u$ , we get: $4 u = 80$ $u = 20$.